Re: [PATCH 2/2] gdb/linux-tdep: move "Perms" column right

[Dominik Czarnota <dominik.b.czarnota@gmail.com>]

Hey,

On Thu, 24 Feb 2022 at 13:18, Simon Marchi <simon.marchi@polymtl.ca> wrote:

> On 2022-02-23 16:41, John Baldwin wrote:
> > On 2/23/22 1:26 PM, Simon Marchi via Gdb-patches wrote:
> >> Commit 29ef4c0699e1 ("gdb/linux-tdep.c: Add Perms to the 'info proc
> >> mappings' output") has broken test gdb.base/info-proc.exp on Linux,
> >> because it changes the output of "info proc mappings" in a way that the
> >> test does not expect (my bad for not testing before pushing).
> >>
> >> I looked at how FreeBSD handles this, since I remembered it did show
> >> permission flags.  It looks like this:
> >>
> >>            Start Addr           End Addr       Size     Offset   Flags
>  File
> >>              0x200000           0x243000    0x43000        0x0  r--
> CN-- /usr/local/bin/tmux
> >>
> >> (I think that `Flags` and the flags not being aligned is not
> >> intentional)
> >>
> >> The test passes on FreeBSD, because the test looks for four hex numbers
> >> in a row and ignores the rest:
> >>
> >>      ".*Mapped address
> spaces:.*${hex}${ws}${hex}${ws}${hex}${ws}${hex}.*"
> >>
> >> I suggest fixing it on Linux by moving the flags column to the same
> >> place as in the FreeBSD output.  It makes things a bit more consistent
> >> between OSes, and we don't have to touch the test.
> >
> > FWIW, the format I chose to use on FreeBSD was to match an existing tool
> > in FreeBSD (procstat(1)).  I wasn't necessarily trying to come up with a
> > cross-platform format.
>
> That's fine, and I don't think we can really have a cross-platform
> format, each OS has different concepts.
>
> > The weird alignment of "Flags" is on purpose as it
> > spans both the permissions field and a separate "flags" field (the 'C'
> > stands for a Copy-On-Write mapping for example).
>
> Ah ok, so it's centered on the column.
>
> > (https://www.freebsd.org/cgi/man.cgi?procstat describes possible flags)
> >
> > I think your change is fine though.
>
> Thanks.  Adding Dominik in CC, I realize he is probably not subscribed
> to gdb-patches.  Does that look good to you?  Here's the link to the
> patch if needed:
>
>   https://sourceware.org/pipermail/gdb-patches/2022-February/186083.html

Yeah, it looks good to me. Thanks a lot for taking care of this.


>
>
> Simon
>

Best regards,
Dominik